A SMALL HIGH RATE THERMAL STORAGE SYSTEM FOR ELECTRIC VEHICLES

THE PROVISION OF ACCEPTABLE LEVELS OF OCCUPANT COMFORT IN AN ELECTRIC VEHICLE (EV) ADDS CONSIDERABLY TO THE LOAD ON THE BATTERY SYSTEM. BATTERIES BARELY STORE ENOUGH ENERGY TO PROVIDE AN ADEQUATE RANGE WITHOUT ANY AUXILIARY LOAD. THE ADDITION OF MAJOR POWER-CONSUMING OPTIONS, SUCH AS AIR CONDITIONING, WILL HAVE TO BE CAREFULLY MANAGED TO PREVENT THIS LIMITED RANGE FROM DROPPING WELL BELOW AN ACCEPTABLE THRESHOLD. A MAJOR AID IN MANAGING AIR CONDITIONING LOADS WILL BE ACHIEVED BY COUPLING A SMALL "COOL" STORAGE SYSTEM WITH THE ACTIVE AIR CONDITIONING (A/C) UNIT. THIS SMALL SYSTEM WILL (1) TAKE CARE OF PEAK LOADS, ALLOWING A SMALLER AND MORE EFFICIENT ACTIVE A/C SYSTEM, (2) HANGLE THE COOLING LOAD WHEN PEAK POWER IS BEING WITHDRAWN FROM THE BATTERY, AND (3) PROVIDE AN EFFECTIVE MEANS OF UTILIZING MODEST LEVELSOF SOLAR ENERGY. SUCH A SYSTEM WILL ALSO OFFER THE UNIQUE ADANTAGE OF BEING ABLE TO PRE-COOL AHOT PASSENGER COMPARTMENT PRIOR TO ENTRY. TYPICAL THERMAL STORAGE MEDIA PRECLUDE HIGH HEAT TRANSFER RATS FROM PHYSICALLY SMALL STORAGE SYSTEMS. HOWEVER, BECAUSE OF CONTINUOUS GAS EVOLUTION AND CONDENSATION, A HIGH THERMAL STORAGE DENSITY CLATHRATE-HYDRATE SYSTEM OFFERS THE POTENTIAL FOR THE NECESSARY HEAT TRANSFER RATES WITHIN THE EV SIZE AND WEIGHT LIMITATIONS. PHASE I WILL QUANTIFY THE MAXIMUM ACHIEVABLE DISCHARGE RATES FOR SEVERAL CLATHRATE HYDRATE SYSTEMS. CHARGE RATE DATA WILL ALSO BE ACCUMULATED ON THE SAME SYSTEMS. THIS HEAT TRANSFER RATE DATA, PLUS REPRESENTATIVE EV THERMAL LOADS AND HEAT PUMP PERFORMANCE, WILL ALLOW A PRELIMINARY SYSTEM DESIGN AND VIABILITY ASSESSMENT.